Javadoc search feature is broken in Java 11

[sjohnr]

Describe the bug
When using the search feature in the javadoc, links take you to a URL like "../undefined/...".

To Reproduce

• Visit api docs snapshot
• Type "OAuth2Authorization" in "SEARCH:".
• Clicking links to classes takes you to 404 Not Found page

Expected behavior
Links work when using the javadoc search feature.

Issue gh-694

[sjohnr]

See https://stackoverflow.com/a/53732633/15835039.